Re-add missing getExtension function
Re-add missing getExtension function

cadam-telpay/flow.js,SuberFu/flow.js,manoj-nama/flowplus,dshefchik/flow.js,manoj-nama/flowplus,evilaliv3/flow.js,eric-seekas/flow.js,SuberFu/flow.js,jerlinjames/flow.js,flowjs/flow.js,flowjs/flow.js,codecentric/flow.js,Symplicity/flow.js